There is a very nice diagram about 3/4 way down the $40 robot page you linked to that show how the transistor and pots get connected.Did you see this diagram?What about it do you not understand?

In the diagram the Collectors do not connect to the pots, The Bases connect to the pots (blue lines).The collectors connect to the +9V (red lines) and the Emitters connect to 1k Ohm resistors (black lines).

thanks for the timely reply.so can i connect just the one collector to the 9v battery or the both on the other side.can i connect it to the potentiometer joint.-another question the potentiometer the track pins of the two are joined leaving one of each at the ends free are they to be connected.

In "Step 3A" of the $40 instructions is the Schematic (symbolic connections of the components). This shows that the one end of the pots go to +V and that the wiper and other end are connected together.

The wiring diagram in Step 3B does not show the wiper to end connection of the pot. It will work either way but connecting the wiper to the other end is better.

I just did a closer comparison of the schematic and the wiring diagram. The Diagram does NOT show all of the connections. Since I've never built this circuit or tried following these instructions I don't know if all to complete or correct but I suspect that it is correct.

Also try searching the forum here to see if anyone else has had these questions.

Thanks I will try it.Also in the 22nd picture both the connections are connected to the 9v battery(the wiper joint) but in the next picture its gone what do you think is the circuit complete with only one connection.And should i connect one collector to the preset joint or both on both sides.?

Submitted by Libraoct7 on November 5, 2010 - 11:20pm.Hi, thank you for your nice tutorial. I have a question.In your picture, you connceted the joints of the emitters to the right and left of the circuit to the track pin of the presets to right and left of the circuit respectively. However, in your diagram you only connected the joints of the emitter to the right circuit to the track pin of the preset ro right circuit. So, which is the correct way?